Required components

Lint rule to validate required components in composite datatype fields.

What it does

Flags composite fields whose required components (as declared by the datatype profile for the message's version) are missing or empty in any repetition. The rule reads profile context attached by @glion/annotate-profile-context, resolves each field's datatype, and checks the required components on every repetition. Empty fields, primitive datatypes, and segments without a known profile are skipped.

Install

npm install @glion/lint-profile-required-components

Use

import { hl7v2AnnotateProfileContext } from "@glion/annotate-profile-context";
import { hl7v2Parser } from "@glion/parser";
import hl7v2LintRequiredComponents from "@glion/lint-profile-required-components";
import { unified } from "unified";
import { reporter } from "vfile-reporter";

const message = [
  "MSH|^~\\&|SENDER|FAC|RECV|RFAC|20250601120000||ADT^A01^ADT_A01|MSG00001|P|2.5",
  "PID|1||PATID1234^^^HOSP^MR||DOE^JANE||19800101|F",
].join("\r");

const file = await unified()
  .use(hl7v2Parser)
  .use(hl7v2AnnotateProfileContext)
  .use(hl7v2LintRequiredComponents)
  .process(message);

console.error(reporter([file]));

API

unified().use(hl7v2LintRequiredComponents)

A unified lint rule plugin. Takes no options.

Reads file.data.profile. For each non-empty field, resolves the datatype definition from the field profile and iterates dtDef.requiredSequences. For every field repetition, checks that each required component is present with a non-empty first subcomponent value.

import type { Plugin } from "unified";
import type { Root } from "@glion/ast";

declare const hl7v2LintRequiredComponents: Plugin<[], Root>;
export default hl7v2LintRequiredComponents;

What it checks

This rule flags missing required components on composite fields. The classic case is MSH-9 (Message Type), where the MSG datatype requires the message code (.1) and trigger event (.2) components.

Valid

MSH-9 carries message code, trigger event, and message structure:

MSH|^~\&|SENDER|FAC|RECV|RFAC|20250601120000||ADT^A01^ADT_A01|MSG00001|P|2.5
PID|1||PATID1234^^^HOSP^MR||DOE^JANE||19800101|F

Invalid

MSH-9.2 (Trigger Event) is empty, which violates the MSG datatype profile in v2.5:

MSH|^~\&|SENDER|FAC|RECV|RFAC|20250601120000||ADT^|MSG00001|P|2.5
PID|1||PATID1234^^^HOSP^MR||DOE^JANE||19800101|F

Reported message:

Required component MSH-9.2 (Trigger Event) is missing or empty

When the component name is available in the datatype profile it appears in parentheses. One message is reported per missing required component per repetition.